3691239 - The attachment is already being referenced by another object or field

While uploading documents to a custom MDF object, there are certain documents which are not uploaded because of the following error.

ERROR: The attachment Attachment1.xxx with ID XXXXXX is already being referenced by another object or field. Please try to export the attachment or download the attachment and upload it again. with the index 0

SAP SuccessFactors HXM Suite

Metadata Framework API (MDF)

OData API

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